Problem: What do the following two equations represent? $x-y = -3$ $x-y = -3$
Putting the first equation in $y = mx + b$ form gives: $x-y = -3$ $-y = -x-3$ $y = 1x + 3$ Putting the second equation in $y = mx + b$ form gives: $x-y = -3$ $-y = -x-3$ $y = 1x + 3$ The above equations turn into the same equation, so they represent equal lines.